In a known image processing device including an image processing unit configured to perform image data processing, multiple modes may be provided for supplying power to the image processing unit to reduce power consumption. For instance, in a multifunction device including a main CPU and a sub CPU, multiple power supply modes for supplying power to those CPUs at different power consumption levels may be provided. In one of the modes in which the power consumption level is set at the lowest, the power supply to the main CPU is shut off and the power is only supplied to the sub CPU. The sub CPU determines whether an input from a user is received.
The image processing device may be idle without receiving an input from the user or image data from an external device while power remains on. In such a case, the power supply to the image processing unit may not be needed. However, in the known image processing device, the power is supplied to the sub CPU in power supply mode in which the power consumption level is set at the lowest. Therefore, the power consumption is not sufficiently reduced.
According to technologies described herein, power consumption while an image processing device is turned on can be reduced in comparison to a configuration in which power is continuously supplied to an image processing unit that performs image data processing.